Gisella Perl was a successful Jewish gynecologist in Romania before WWII. In 1944, she was sent to Auschwitz and put to work in the infirmary, taking care of prisoners without any anesthesia or even antibiotics and bandages to help assuage their pain.

She was also forced to assist Dr. Josef Mengele, who was notorious for "experimenting on" (which often meant torturing, more or less) certain groups of people — specifically pregnant women, twins, and the physically handicapped — before sending them to the gas chambers. Once she realized how Mengele was treating the pregnant women, she started giving them undercover abortions with her bare hands. The Holocaust History Project has all the amazing details:

In an interview with Nadine Brozan for the New York Times in 1982, Dr. Perl recalled her initial experiences with Dr. Mengele's "cure" for pregnancy in Auschwitz. ''Dr. Mengele told me that it was my duty to report every pregnant woman to him,'' Dr. Perl said. ''He said that they would go to another camp for better nutrition, even for milk. So women began to run directly to him, telling him, 'I am pregnant.' I learned that they were all taken to the research block to be used as guinea pigs, and then two lives would be thrown into the crematorium. I decided that never again would there be a pregnant woman in Auschwitz.''

After Dr. Perl's startling realization of the fates of the pregnant women discovered by Dr. Mengele, she began to perform surgeries that before the war she would have believed herself incapable of - abortions. In spite of her professional and religious beliefs as a doctor and an observant Jew, Dr. Perl began performing abortions on the dirty floors and bunks of the barracks in Auschwitz "using only my dirty hands." Without any medical instruments or anesthesia, and often in the cramped and filthy bunks within the women's barracks, Dr. Perl ended the lives of the fetuses in their mothers' womb (estimated at around 3,000) in the hopes that the mother would survive and later, perhaps, be able to bear children.

In some instances, the pregnancy was too far along to be able to perform an abortion. In these cases Dr. Perl broke the amnionic sac and manually dilated the cervix to induce labor. In these cases, the premature infant (not yet completely developed), died almost instantly. Without the threat of their pregnancy being discovered, women were able to work without interruption, gaining them a temporary reprieve from their death sentences.